Adhesive resin composition and bonding method

ABSTRACT

The present invention relates to an inexpensive adhesive resin composition which is applicable even to a base material having a poor bonding property. The adhesive resin composition comprises (A) a polymer having no radical-polymerizable double bond and (B) a radical generating agent in which the radical generating agent (B) is present in an amount of 0.1 to 10 parts by weight on the basis of 100 parts by weight of the polymer (A). In the preferred embodiment of the present invention, the adhesive resin composition further comprises (C) a radical-polymerizable monomer wherein the monomer (C) is present in an amount of 0.1 to 10 parts by weight on the basis of 100 parts by weight of the polymer (A). The radical-polymerizable monomer (C) is a glycidyl group-containing monomer, and the glycidyl group-containing monomer is 4-hydroxybutyl acrylate glycidyl ether.

TECHNICAL FIELD

The present invention relates to an adhesive resin composition and abonding method.

BACKGROUND ART

Conventionally, various materials such as metals, glass, wood andplastics have been used as a base material in industrial applications,etc. Also, there have been provided various adhesives for bonding thesebase materials to other materials. In addition, in order to impartvarious properties such as a rust-proof property, an impact resistance,a water resistance and a weather resistance to these base materials,there have been provided various paints, resin films and coating agents,etc.

However, polyolefin-based plastic materials such as, for example,typically polypropylene, have such a problem that the materials tend tobe deteriorated by themselves in bonding property and coatability owingto non-polarity and crystallizability thereof, although they areexcellent in properties required as the base material. Therefore, thesebase materials are generally subjected to bonding and coating only afterbeing previously subjected to surface treatments such as chemicaltreatment, corona discharge treatment and flame treatment. However, theeffects of these surface treatments tend to be hardly stabilized owingto adverse influence by shapes of the base materials. In addition, thesurface treatments tend to require use of special facilities, resultingin complicated process.

In addition to the above surface treatments, there is also known amethod of directly modifying the base materials themselves to improvetheir bonding property and coatability by previously subjecting thesematerials to chlorination, grafting, etc. However, this method has sucha drawback that it is not effective to improve a bonding property, acoatability, etc., of the existing base materials. In consequence, atpresent, any suitable method which is capable of effectively improving abonding property or a coatability of the base materials withoutsubjecting the materials to pretreatments, has not still beenestablished.

On the other hand, as special adhesive materials, there have beenproposed a resin composition comprising a specific polyolefin obtainedby oxidative degradation (Patent Document 1) and a block copolymerobtained by bonding an isotactic polypropylene having a (mmmm) pentadcontent of 10 to 60% based on whole pentads therein to a polargroup-containing polyolefin (Patent Document 2). However, these adhesivematerials are very expensive.

Patent Document 1: Japanese Patent Application Laid-Open (KOKAI) No.6-192617

Patent Document 2: Japanese Patent Application Laid-Open (KOKAI) No.2005-48172

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

The present invention has been accomplished in view of the aboveconventional problems. An object of the present invention is to providean inexpensive adhesive resin composition which is applicable even tobase materials having a poor bonding property.

Means for Solving the Problem

As a result of the present inventors' earnest study, the followingfinding has been attained. That is, it has been unexpectedly found thatwhen adding a radical generating agent to polymers obtained bypolyaddition reaction such as, for example, urethane resins asgeneral-purpose resins even though they have no radical-polymerizablebond, the resulting composition can exhibit an effective bondingproperty to the base materials.

The present invention has been attained on the basis of the abovefinding. In a first aspect of the present invention, there is providedan adhesive resin composition comprising (A) a polymer having noradical-polymerizable double bond and (B) a radical generating agent,the radical generating agent (B) being present in an amount of 0.1 to 10parts by weight on the basis of 100 parts by weight of the polymer (A).In a second aspect of the present invention, there is provided a bondingmethod comprising the step of applying the above adhesive resincomposition onto a base material to generate a radical derived from theradical generating agent (B). The adhesive resin composition accordingto the preferred embodiment of the present invention further comprises asmall amount of (C) a radical-polymerizable monomer.

EFFECT OF THE INVENTION

According to the adhesive resin composition of the present invention,even when applying the composition to a base material having a lowpolarity and a poor bonding property such as, for example,polypropylene, it is possible to impart a good bonding property to itsportion to be bonded without previously subjecting the base material tosurface treatments such as corona discharge treatment or pretreatmentsfor modifying properties of the base material itself such aschlorination and grafting. Therefore, the adhesive resin composition ofthe present invention can be used for bonding various kinds of basematerials to each other, or upon painting or coating the base material.

PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION

The present invention is described in detail below. However, thefollowing description relates to typical embodiments of the presentinvention, and not intended to limit a scope of the present inventionthereto.

The adhesive resin composition of the present invention comprises (A) apolymer having no radical-polymerizable double bond and (B) a radicalgenerating agent. In the preferred embodiment of the present invention,the adhesive resin composition further comprises (C) aradical-polymerizable monomer. In addition, the adhesive resincomposition of the present invention may also be diluted with water or asolvent according to applications and objects thereof.

Examples of the polymer (A) having no radical-polymerizable double bondinclude urethane resins, melamine resins, epoxy resins, polyesterresins, polyamide resins, polycarbonate resins, high-densitypolyethylene and polypropylene. These polymers may be produced bypolyaddition, addition condensation, polycondensation, ring-openingpolymerization and ion polymerization (addition polymerization).Further, there may also be used acrylic resins such as acrylate resinsobtained by radical polymerization as well as polyolefin resins such aslow-density polyethylene. In the polymers obtained by radicalpolymerization, radical-polymerizable double bonds which havecontributed to the chain reaction are dissipated by termination reactionand, therefore, do not remain therein. The molecular weight of thepolymer (A) is not particularly limited, and the polymer (A) may beselected from those resins generally used with an optional molecularweight.

Examples of the radical generating agent (B) include thermalpolymerization initiators, photopolymerization initiators andphotosensitizers. These agents may be optionally selected according tokinds of energies applied.

Specific examples of the thermal polymerization initiators includeazo-based initiators, ketone peroxide-based initiators,peroxyketal-based initiators, hydroxyperoxide-based initiators,dialkylperoxide-based initiators, diacylperoxide-based initiators,peroxyester-based initiators and peroxydicarbonate-based initiators.These thermal polymerization initiators may be optionally selectedaccording to the base material used, a relationship between heatresistance, curing conditions, etc., of the polymer (A) and half-lifeperiod temperature of the thermal polymerization initiators, andcapability of mixing with the polymer (A). The suitable heatingtemperature upon using these thermal polymerization initiators isusually 40 to 200° C.

Specific examples of the photopolymerization initiators and thephotosensitizers include benzophenone-based initiators, diketone-basedinitiators, acetophenone-based initiators, benzoin-based initiators,thioxanthone-based initiators and quinone-based initiators. Thesephotopolymerization initiators and the photosensitizers may beoptionally selected according to wavelength of light irradiated andcapability of mixing with the polymer (A). The suitable irradiation doseof ultraviolet light is generally 100 to 2000 mJ/cm² in terms ofcumulative light amount when using a 80 W metal halide lamp.

The radical generating agent (B) is used in an amount of 0.1 to 10 partsby weight and preferably 0.2 to 3 parts by weight on the basis of 100parts by weight of the polymer (A). When the amount of the radicalgenerating agent (B) used is less than the above-specified range,generation of radicals tends to be insufficient, thereby failing toattain a desired bonding property. Even when the amount of the radicalgenerating agent (B) used is more than the above-specified range, it maybe difficult to attain a high bonding property corresponding to such alarge amount used. Meanwhile, these radical generating agents (B) may beused in combination of any two or more thereof.

As the radical-polymerizable monomer (C), there are usually used thosemonomers having at least one carbon-to-carbon unsaturated bond having aradical polymerizability in a molecule thereof. Theradical-polymerizable monomer (C) may be used for the purpose ofenhancing the effects of the present invention. Examples of thecarbon-to-carbon unsaturated bond having a radical polymerizabilityinclude a vinyl group, an aryl group and a (meth)acryloyl group. In thepresent invention, it is preferred that the monomer (C) further compriseone or more reactive substituent groups which are bonded to differentpositions from that of the carbon-to-carbon unsaturated bond having aradical polymerizability. Examples of the reactive substituent groupsinclude an epoxy group, a carboxyl group, a hydroxyl group, an aminogroup, an amide group, a carbonyl group and a cyano group. Among thesereactive substituent groups, a glycidyl group as one kind of epoxy groupis preferred. The more preferred monomers (C) are those in which thedistance between bonding positions of the reactive substituent groups inthe same molecule is larger.

Specific examples of the radical-polymerizable monomer (C) include alkyl(meth)acrylates such as methyl acrylate, methyl methacrylate, ethylacrylate, n-butyl acrylate, 2-ethylhexyl methacrylate and cyclohexylmethacrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxybutylacrylate, 4-hydroxybutyl acrylate, 1,4-cyclohexanedimethanolmonoacrylate and 2-hydroxypropyl methacrylate; epoxyalkyl(meth)acrylates such as glycidyl methacrylate and 4-hydroxybutylacrylate glycidyl ether (hereinafter referred to merely as “4HBAGE”);unsaturated carboxylic acids such as acrylic acid and methacrylic acid;(N-substituted) (meth)acrylamides such as acrylamide, diacetoneacrylamide and N-methylol methacrylamide; and compounds having aplurality of radical-polymerizable carbon-to-carbon unsaturated bonds inthe same molecule such as 1,6-hexanediol diacrylate, trimethyloipropanetriacrylate and 1,3,5-triaryl isocyanates, as well as generally usedmonomers such as vinyl acetate, mesityl oxide, 4-hydroxybutyl vinylether and aryl glycidyl ethers. In the present invention, among thesemonomers, especially preferred is 4HBAGE.

The radical-polymerizable monomer, (C) is used in an amount of 0.1 to 10parts by weight and preferably 0.5 to 5 parts by weight on the basis of100 parts by weight of the polymer (A). Even when the amount of theradical-polymerizable monomer (C) used is more than the above-specifiedrange, it may be difficult to attain a high bonding propertycorresponding to such a large amount used, and further there tends tooccur problems such as malodor and stickiness of the resin owing to theradical-polymerizable monomer (C) partially remaining in an unreactedstate in the resin. Meanwhile, these radical-polymerizable monomers (C)may be used in combination of any two or more thereof.

Examples of the base material to which the adhesive resin composition ofthe present invention is applied include polyethylene, polypropylene,polystyrene, polycarbonates, polyethylene terephthalate and polyamides.In addition, in the present invention, the surface treatments which are,in general, previously conducted for less adhesive base materials (suchas, for example, corona discharge treatment) may be optional. However,by conducting these surface treatments, it is possible to attain a stillhigher effects of the present invention.

In the bonding method according to the present invention, the adhesiveresin composition of the present invention is applied onto the basematerial to generate a radical derived from the radical generatingagent. In general, the adhesive resin composition may be diluted withwater or a solvent to adequately control a concentration of thecomposition upon use. In the present invention, before generating theradical, a coating film obtained by applying the composition onto thebase material may be cured. That is, after uniformly coating the basematerial with a dilute solution of the adhesive resin composition of thepresent invention to form a coating film thereon, the coating film maybe heated or dried to form a firm resin layer. The radical may begenerated from the radical generating agent by applying energies such asheat and light (for example, ultraviolet light) thereof. The generationof the radical may be carried out at an optional time after forming thecoating film by applying the adhesive resin composition of the presentinvention onto the base material. Usually, when curing the coating filmby heating, the radical derived from the thermal polymerizationinitiator may be generated simultaneously with the heating.

The reason why the bonding property of the polymer (A) having noradical-polymerizable double bond to the base material is enhanced byaction of the radical generating agent (3) is considered as follows,though it is not clearly determined. That is, it is suggested that thepolymer (A) and/or the surface of the base material undergo certainchemical change by action of the radical generating agent (B).

EXAMPLES

The present invention is described in more detail below by the followingexamples. However, these examples are only illustrative and not intendedto limit a scope of the present invention thereto.

<Production of Various Test Specimens>

In the following examples, etc., various test specimens were produced bythe following procedure and subjected to peel test.

<Selection and Processing of Base Material>

The following kinds of test pieces (all having a thickness of 1 mm)produced by Nippon Test Panel Co., Ltd., were formed all into a stripshape having a longer side length of 70 mm and a shorter side length of25 mm principally without being subjected to any surface treatments suchas corona discharge treatment to thereby produce various test specimens.Meanwhile, any surface treatment, if otherwise conducted, wasindividually specified in the respective examples, etc. As therespective test pieces, there were used those formed from polycarbonates(hereinafter referred to merely as “PC”), polyethylene terephthalate(hereinafter referred to merely as “PET”), nylon 6 and polypropylene(hereinafter referred to merely as “PP”).

<Selection and Processing of Nonwoven Fabric>

A nylon spun bonded fabric “WiWi” (tradename; product number:“R1005WTO”) produced by Unitika Co., Ltd., was formed into a strip shapehaving a longer side length of 150 mm and a shorter side length of 25 mmto thereby produce various test specimens.

<Formulation of Adhesive Resin Composition>

Using various resins shown in the respective Examples, etc., therespective components were blended together at the following weightratio to produce an adhesive resin composition. The solid content ratiobetween the resin, the radical-polymerizable monomer and the radicalgenerating agent (resin/radical-polymerizable monomer/radical generatingagent) in the blended mixture was adjusted to 100/3/1. Meanwhile, whenusing the radical-polymerizable monomer, at least one monomer selectedfrom the group consisting of 4HBAGE, glycidyl methacrylate (hereinafterreferred to merely as “GMA”), acrylic acid and methacrylic acid wasblended in the composition, and the use of the monomer is specified inthe respective Examples, etc. Also, when using the radical generatingagent, “KAYAESTER 0-50” (tradename; chemical substance name:t-butylperoxy-2-ethyl hexanoate) produced by Kayaku-Akzo Co., Ltd., or“PERCUMYL H” (tradename; chemical substance name: cumene hydroperoxide)produced by Nippon Oils and Fats Co., Ltd., was blended in thecomposition, and the use of the radical generating agent is specified inthe respective Examples, etc.

<Epoxy Resin>

As an epoxy resin, there was used a mixture obtained by blending“EPICOAT 828” (tradename; epoxy resin) and “EPICURE 3080” (tradename;curing agent) both produced by Japan Epoxy Resin Co., Ltd., with eachother at a weight ratio of 10/3.

<Acrylic Resin>

As an acrylic resin, there was used a mixture obtained by blending“RIKABOND ES-620” (tradename; acrylic resin) and “RIKABOND ES-800”(tradename; acrylic resin) with each other at a weight ratio of 1/1.

<Urethane Resin>

As a urethane resin, there was used “U-COAT UWS-145” (tradename;polyester-based urethane resin) produced by Sanyo Kasei Co., Ltd., or“U-COAT UWS-2505” (tradename; polyether-based urethane resin) producedby Sanyo Kasei Co., Ltd. Further, there was used a polyurethanedispersion “PUD101” (product name developed by Nippon Kasei Co., Ltd.;polyether-based urethane resin) which was produced by the followingmethod.

<Method for Production of PUD101>

A reactor was charged with 196.3 g of polytetramethylene ether glycol(“PTMG 1000” produced by Mitsubishi Chemical Corp.) having a molecularweight of 1,000, 129.1 g of isophorone diisocyanate and 17.2 g ofdimethylolbutanoic acid, and the contents of the reactor were reactedwith each other at 70° C. for 7 hr under a nitrogen flow, therebyobtaining a polyurethane resin. To the thus obtained polyurethane resinwas added 11.7 g of triethylamine to neutralize the polyurethane resin.Successively, while stirring the resulting reaction mixture using ahomomixer, 571.5 g of desalted water was added thereto. To the obtainedpolyurethane resin dispersion was added an aqueous solution prepared bymixing 14.5 g of a 80% aqueous solution of hydrazine hydrate in 59.7 gof water, while stirring using a homomixer, to conduct a chain extensionreaction thereof, thereby finally obtaining the aqueous polyurethaneresin dispersion “PUD101”.

<Application of Adhesive Resin Composition onto Base Material>

Using a bar coater, the adhesive resin composition was uniformly appliedonto the base material such that the resulting resin layer after dryinghad a thickness of 0.07 mm. Meanwhile, the adhesive resin compositionwas applied over a region of the base material extending from one of itsshorter sides to the position spaced apart by 50 mm from the shorterside.

<Compression-Bonding of Nonwoven Fabric to Base Material and ResinLayer>

The nonwoven fabric was superimposed on the resin layer formed on thebase material such that the shorter side end of the base material on itsside to which the adhesive resin composition has been applied wasaligned with one of shorter sides of the nonwoven fabric, and furtherlonger sides of the base material and the nonwoven fabric were alignedwith each other. The resulting laminate was lightly compression-bondedto each other using a roll. Thereafter, the compression-bonded productwas allowed to stand at room temperature for 30 min to subject it topreliminary drying.

<Curing of Resin Layer>

The respective pre-dried test specimens were placed in an oven preheatedat 80° C. to cure the resin layer thereof at 80° C. for 5 hr underheating. Thereafter, the respective test specimens were taken out of theoven, cooled to room temperature, and then subjected to peel test.

<Method of Generating a Radical>

Simultaneously with heat-curing the resin layer, the radical generatingagent was thermally decomposed by the heat to thereby generate aradical.

<Peel Test Method>

Using a constant rate extension type tensile tester “TENSILON RTM-500”manufactured by Orientec Co., Ltd., the respective test specimens weresubjected to 90° peel strength test by drawing the base material and thenonwoven fabric thereof (at a pulling rate of 50 mm/min) to measure astrength of peeling between bonding surfaces of the base material andthe resin layer. The thus measured peel strength of the respective testspecimens was compared with that of a comparative test specimen (testspecimen prepared by using an adhesive resin composition formed from theresin having no radical polymerizability solely) to examine the effectof improving a bonding property thereof. Meanwhile, the unit of themeasured peel strength value is “kg/25 mm” because all of the testspecimens used were commonly configured to have a bonding width of 25mm.

Example 1 and Comparative Example 1 Epoxy Resin

An epoxy resin in the form of a mixture comprising “EPICOAT 828” and“EPICURE 3080” at a weight ratio 10/3 was used as a resin to evaluate abonding property thereof to nylon 6. In addition, in the respectiveExamples, in order to generate a radical, “KAYAESTER 0-50” as a radicalgenerating agent was added to the epoxy resin. The results are shown inTable 1 below. Meanwhile, the respective radical-polymerizable monomersused are as described in the following parentheses: Comparative Example1 (none); Example 1-1 (none); Example 1-2 (GMA); and Example 1-3(4HBAGE).

TABLE 1 Peel strength Radical generating (kg/25 mm) agent Monomer Nylon6 Comparative None None 0.34 Example 1 Example 1-1 KAYAESTER 0-50 None0.52 Example 1-2 KAYAESTER 0-50 GMA 1.24 Example 1-3 KAYAESTER 0-504HBAGE 1.92

Example 2 and Comparative Example 2 Acrylic Resin

An acrylic resin in the form of a mixture comprising “RIKABOND ES-620”and “RIKABOND ES-800” at a weight ratio 1/1 was used as a resin toevaluate a bonding property thereof to PC and nylon 6. In addition, inthe respective Examples, in order to generate a radical, “PERCUMYL H” asa radical generating agent was added to the acrylic resin. The resultsare shown in Table 2 below. Meanwhile, the respectiveradical-polymerizable monomers used are as described in the followingparentheses: Comparative Example 2 (none); Example 2-1 (none); Example2-2 (GMA); and Example 2-3 (4HBAGE).

TABLE 2 Peel strength Radical (kg/25 mm) generating agent Monomer PCNylon 6 Comparative None None 1.00 1.09 Example 2 Example 2-1 PERCUMYL HNone 1.06 1.58 Example 2-2 PERCUMYL H GMA 1.30 2.11 Example 2-3 PERCUMYLH 4HBAGE 2.37 2.16

Example 3 and Comparative Example 3 Polyether-Based Urethane Resin

A polyether-based urethane resin “PUD101” was used as a resin toevaluate a bonding property thereof to PET, nylon 6, PP and coronadischarge-treated PP. In addition, in the respective Examples, in orderto generate a radical, “PERCUMYL H” as a radical generating agent wasadded to the polyether-based urethane resin. The results are shown inTable 3 below. Meanwhile, the respective radical-polymerizable monomersused are as described in the following parentheses: Comparative Example3 (none); Example 3-1 (none); Example 3-2 (GMA); and Example 3-3(4HBAGE). The “corona discharge-treated PP” means such a materialobtained by previously subjecting a surface of PP as a base material tocorona discharge treatment under a voltage of 15,000 V 20 times using anapparatus “PS-1” manufactured by Shin-Koh Denki Kelso Co., Ltd.

TABLE 3 Peel strength Radical (kg/25 mm) generating Nylon Coronadischarge- agent Monomer PET 6 PP treated PP Comparative None None 0.670.15 0.47 2.20 Example 3 Example 3-1 PERCUMYL H None 1.41 1.34 0.63 2.94Example 3-2 PERCUMYL H GMA 1.39 1.37 0.85 3.50 or more* Example 3-3PERCUMYL H 4HBAGE 1.39 1.59 1.43 3.50 or more* Note *As to the peelstrength relative to the corona discharge-treated PP in Examples 3-2 and3-3, since the nonwoven fabric was broken and ruptured earlier thanoccurrence of peeling between the bonding surfaces owing to enhancedbonding property, the peel strength is expressed by a strength at break.

Example 4 and Comparative Example 4 Polyester-Based Urethane Resin

A polyester-based urethane resin “U-COAT UWS-145” was used as a resin toevaluate a bonding property thereof to nylon 6, and PET. In addition, inthe respective Examples, in order to generate a radical, “PERCUMYL H” asa radical generating agent was added to the polyester-based urethaneresin. The results are shown in Table 4 below. Meanwhile, the respectiveradical-polymerizable monomers used are as described in the followingparentheses: Comparative Example 4 (none); Example 4-1 (none); Example4-2 (GMA); and Example 4-3 (4HBAGE).

TABLE 4 Peel strength Radical (kg/25 mm) generating agent Monomer PETNylon 6 Comparative None None 1.20 1.69 Example 4 Example 4-1 PERCUMYL HNone 1.53 1.71 Example 4-2 PERCUMYL H GMA 3.50 or 2.65 more* Example 4-3PERCUMYL H 4HBAGE 3.50 or 2.65 more* Note *As to the peel strengthrelative to PET in Examples 4-2 and 4-3, since the nonwoven fabric wasbroken and ruptured earlier than occurrence of peeling between thebonding surfaces owing to enhanced bonding property, the peel strengthis expressed by a strength at break.

Example 5 and Comparative Example 5 Polyether-Based Urethane Resin

A polyether-based urethane resin “U-COAT UWS-2505” was used as a resinto evaluate a bonding property thereof to PET. In addition, in therespective Examples, in order to generate a radical, “PERCUMYL H” as aradical generating agent was added to the polyether-based urethaneresin. The results are shown in Table 5 below. Meanwhile, respectiveradical-polymerizable monomers used are as described in the followingparentheses: Comparative Example 5 (none); Example 5-1 (none); Example5-2 (acrylic acid); Example 5-3 (methacrylic acid); Example 5-4 (GMA);and Example 5-5 (4HBAGE).

TABLE 5 Peel strength Radical generating (kg/25 mm) agent Monomer PETComparative None None 0.62 Example 5 Example 5-1 PERCUMYL H None 0.70Example 5-2 PERCUMYL H Acrylic 1.00 acid Example 5-3 PERCUMYL HMethacrylic 1.17 acid Example 5-4 PERCUMYL H GMA 1.25 Example 5-5PERCUMYL H 4HBAGE 3.50

1. An adhesive resin composition comprising (A) a polymer having noradical-polymerizable double bond and (B) a radical generating agent,the radical generating agent (B) being present in an amount of 0.1 to 10parts by weight on the basis of 100 parts by weight of the polymer (A).2. An adhesive resin composition according to claim 1, wherein thepolymer (A) having no radical-polymerizable double bond is at least oneresin selected from the group consisting of urethane resins, melamineresins, epoxy resins, acrylic resins, polyester resins, polyamideresins, polycarbonate resins and polyolefin resins.
 3. An adhesive resincomposition according to claim 1, further comprising (C) aradical-polymerizable monomer, wherein the monomer (C) is present in anamount of 0.1 to 10 parts by weight on the basis of 100 parts by weightof the polymer (A).
 4. An adhesive resin composition according to claim3, wherein the radical-polymerizable monomer (C) is a glycidylgroup-containing monomer.
 5. An adhesive resin composition according toclaim 4, wherein the glycidyl group-containing monomer is 4-hydroxybutylacrylate glycidyl ether.
 6. A bonding method comprising the step ofapplying the adhesive resin composition as defined in claim 1 onto abase material to generate a radical derived from the radical generatingagent (B).